Question

Aerenchyma is formed by_____________

• A. Parenchyma
• B. Collenchyma
• C. Scelerenchyma
• D. Xylem

Answer 1

Answer: (A)

Parenchyma

• Aerenchyma cells are present in the aquatic plant. Such cells have large air cavities, which enable the plant to float in water.
• Collenchyma cells are living, elongated and irregularly thickened at corners with less intercellular space. They do not have air cavities to provide buoyancy in water. Therefore, option B is incorrect.
• Sclerenchyma is dead, long, thin, narrow cells with thickened walls without any internal space. These cells have a narrow lumen. Hence cannot have a large air cavity for buoyancy. Therefore, option C is incorrect.

Xylem is a vascular or conductive tissue of the plant. Their main function is to carry out the conduction of water and minerals in the plant.

• Parenchyma cells are thin-walled, flexible and loosely packed cells. They have large central vacuole. They carry out many functions in plants. They are often alive at maturity. Their shape changes as per function. Such parenchyma cells have large air cavities to give buoyancy to the plant and enable them to float in water. These cells are called aerenchyma. Hence, option A is correct.

Therefore, option D is incorrect.